Merge pull request #453

.travis.yml

@@ -61,7 +61,6 @@ matrix:
 
 before_script:
   - mongod --version
-  - mongo --eval 'var v = db.runCommand({buildInfo:1}).versionArray; if ((v[0] == 3 && v[1] >= 4) || v[0] >= 4) db.adminCommand({setFeatureCompatibilityVersion:"3.4"});'
   - pecl install -f mongodb-${DRIVER_VERSION}
   - php --ri mongodb
   - composer install --dev --no-interaction --prefer-source

tests/FunctionalTestCase.php

@@ -11,6 +11,7 @@ use MongoDB\Model\BSONDocument;
 use InvalidArgumentException;
 use stdClass;
 use Traversable;
+use UnexpectedValueException;
 
 abstract class FunctionalTestCase extends TestCase
 {
@@ -76,20 +77,32 @@ abstract class FunctionalTestCase extends TestCase
         );
     }
 
-    protected function getFeatureCompatibilityVersion()
+    protected function getFeatureCompatibilityVersion(ReadPreference $readPreference = null)
     {
         if (version_compare($this->getServerVersion(), '3.4.0', '<')) {
-            return $this->getServerVersion();
+            return $this->getServerVersion($readPreference);
         }
+
         $cursor = $this->manager->executeCommand(
-            "admin",
-            new Command(['getParameter' => 1, 'featureCompatibilityVersion' => 1])
+            'admin',
+            new Command(['getParameter' => 1, 'featureCompatibilityVersion' => 1]),
+            $readPreference ?: new ReadPreference(ReadPreference::RP_PRIMARY)
         );
 
         $cursor->setTypeMap(['root' => 'array', 'document' => 'array']);
         $document = current($cursor->toArray());
 
-        return $document['featureCompatibilityVersion']['version'];
+        // MongoDB 3.6: featureCompatibilityVersion is an embedded document
+        if (isset($document['featureCompatibilityVersion']['version']) && is_string($document['featureCompatibilityVersion']['version'])) {
+            return $document['featureCompatibilityVersion']['version'];
+        }
+
+        // MongoDB 3.4: featureCompatibilityVersion is a string
+        if (isset($document['featureCompatibilityVersion']) && is_string($document['featureCompatibilityVersion'])) {
+            return $document['featureCompatibilityVersion'];
+        }
+
+        throw new UnexpectedValueException('Could not determine featureCompatibilityVersion');
     }
 
     protected function getPrimaryServer()
@@ -108,7 +121,11 @@ abstract class FunctionalTestCase extends TestCase
         $cursor->setTypeMap(['root' => 'array', 'document' => 'array']);
         $document = current($cursor->toArray());
 
-        return $document['version'];
+        if (isset($document['version']) && is_string($document['version'])) {
+            return $document['version'];
+        }
+
+        throw new UnexpectedValueException('Could not determine server version');
     }
 
     /**